The invention concerns a method of starting an internal combustion engine, in particular a stationary gas engine, wherein the internal combustion engine is driven by at least one starter motor. After starting of the starter motor, the starting process is broken off if the angular acceleration of the internal combustion engine remains below a predeterminable acceleration value and/or if within a predeterminable first time the actual rotary speed remains below a predeterminable first rotary speed threshold value and/or within a predeterminable second time the average rotary speed of the internal combustion engine remains below a predeterminable second rotary speed threshold value.
The invention further concerns a starter system for starting an internal combustion engine, in particular a stationary gas engine, with at least one starter motor to which energy can be fed by an energy source. The starter motor can be connected to a drive shaft of the internal combustion engine by which the drive shaft is drivable. A control device monitors the actual rotary speed and/or the angular speed and/or the angular acceleration of the internal combustion engine, and the control device stops or activates the feed of energy to the at least one starter motor in dependence on the actual rotary speed and/or the angular speed and/or the angular acceleration.
Methods of starting an internal combustion engine in which the rotary speed of the internal combustion engine is used as a criterion for interrupting a starting process are already known (for example DE 102 45 640 B3, FR 2 927 301 A1 and JP 2006-063867 A).
If in an internal combustion engine, water penetrates into the combustion chamber of one or more cylinders while the engine is stationary, then the incompressible water can cause damage to the connecting rod and/or piston in a conventional starting process for the internal combustion engine. The water penetrating into the combustion chamber can be for example cooling water from a leaking coolant conduit. If the internal combustion engine were to be completely started in a condition of partially flooded cylinders, water hammer occurs. In that case, the piston in question is abruptly decelerated at the upper position in the compression cycle by the incompressible water, and that can cause engine damage. Moisture sensors, for example, can be used to detect water or moisture in a cylinder of an internal combustion engine. However such sensors cannot distinguish between normal condensate water which can occur in the case of large stationary internal combustion engines because of the chimney effect of the exhaust installation, and dangerous flooding of the cylinder.
Water in a cylinder can be detected by the internal combustion engine accelerating more slowly as a consequence of an increased level of resistance because of the water in the cylinder, than in the normal condition, upon being actuated by the at least one starter motor. During the starting process, therefore, the actual rotary speed and/or the angular speed and/or the angular acceleration of the internal combustion engine can be measured and anomalies can be detected by comparison with predeterminable limit values.
If therefore the measured angular acceleration of the internal combustion engine remains below a predeterminable acceleration value, and/or within a predeterminable first time the actual rotary speed remains below a predeterminable first rotary speed limit value, and/or within a predeterminable second time the average rotary speed of the internal combustion engine remains below a predeterminable second rotary speed limit value, the starting operation can then be interrupted before the internal combustion engine suffers damage due to water hammer.